I would like to upgrade my DSL tariff (currently S) to M, can someone help me with this? I tried calling customer service and send a Whatsapp message but couldn’t reach anyone.
Separately, I cannot register for Mein O2, because they ask me for my landline number which I don’t know. I do not have any documents that show this number -- my bills that go to my email account do not show it, and I never received a contract that showed this number. Please help me fix this, thank you!